System and method of controlling construction machinery

ABSTRACT

A control system for construction machinery includes an upper camera installed in a driver cabin to photograph the front of the driver cabin, a lower camera installed in a vehicle body to photograph the front of the vehicle body, a work apparatus posture detection portion configured to detect a posture of the work apparatus connected rotatably to the vehicle body, an image processing portion configured to synthesize first and second images captured from the upper camera and the lower camera into one image, and configured to transparency-process at least one of the first and second images in the synthesized image according to the posture of the work apparatus detected by the work apparatus posture detection portion, and a display device configured to display the synthesized image transparency-processed by the image processing portion.

PRIORITY STATEMENT

This application claims priority under 35 U.S.C. § 119 to Korean PatentApplication No. 10-2020-0002258, filed on Jan. 7, 2020 in the KoreanIntellectual Property Office (KIPO), the contents of which are hereinincorporated by reference in their entirety.

BACKGROUND 1. Field

Example embodiments relate to a control system and method forconstruction machinery. More particularly, example embodiments relate toa control system for recognizing forward obstacles when working ordriving construction machinery such as a wheel loader, an excavator,etc., and a method of controlling construction machinery using the same.

2. Description of the Related Art

In general, construction machinery such as a wheel loader, an excavator,etc., is widely used to excavate sand, gravel, and the like and load itinto a dump truck. These works may be performed by driving a workapparatus installed in the construction machinery such as a bucket and aboom. However, the work apparatus may obstruct or limit an operator'sfront view while driving, and thus, obstruction of the operator's frontview by the work apparatus may cause a safety accident.

SUMMARY

Example embodiments provide a control system for construction machinerycapable of improving forward visibility limited by a work apparatus.

Example embodiments provide a control method for construction machineryusing the control system.

According to example embodiments, a control system for constructionmachinery includes an upper camera installed in a driver cabin tophotograph the front of the driver cabin, a lower camera installed in avehicle body to photograph the front of the vehicle body, a workapparatus posture detection portion configured to detect a posture ofthe work apparatus connected rotatably to the vehicle body, an imageprocessing portion configured to synthesize first and second imagescaptured from the upper camera and the lower camera into one image, andconfigured to transparency-process at least one of the first and secondimages in the synthesized image according to the posture of the workapparatus detected by the work apparatus posture detection portion, anda display device configured to display the synthesized imagetransparency-processed by the image processing portion.

In example embodiments, the image processing portion maytransparency-process the first image in the synthesized image when atleast a part of the work apparatus invades a predetermined position, andthe image processing portion may transparency-process the second imagein the synthesized image when the work apparatus does not invade thepredetermined position.

In example embodiments, the entire display area of the display devicemay include a predetermined transparency processing area and an externalarea of the transparency processing area, and the image processingportion may process the first and second images to be transparent in thetransparency processing area.

In example embodiments, the control system for construction machinerymay further includes an input portion configured to set an imageprocessing condition in the image processing portion.

In example embodiments, the image processing condition may include atransparency processing switching timing of the first and second imagesor the transparency processing area of the entire display area of thedisplay device.

According to example embodiments, in a method of controllingconstruction machinery, a first image of the front of a driver cabin isobtained from an upper camera installed in the drive cabin. A secondimage of the front of a vehicle body is obtained from a lower camerainstalled in the vehicle body. A posture of a work apparatus connectedto the vehicle body is detected. The first and second images aresynthesized into one image. At least one of the first and second imagesin the synthesized image is transparency-processed according to thedetected posture of the work apparatus. The transparency-processed imageis displayed through a display device.

In example embodiments, transparency-processing the at least one of thefirst and second images may include transparency-processing the firstimage in the synthesized image when at least a part of the workapparatus invades a predetermined position, and transparency-processingthe second image in the synthesized image when the work apparatus doesnot invade the predetermined position.

In example embodiments, the entire display area of the display devicemay include a predetermined transparency processing area and an externalarea of the transparency processing area, and the first and secondimages may be processed to be transparent in the transparency processingarea.

In example embodiments, the method may further include setting an imageprocessing condition for transparency processing of the first and secondimages.

In example embodiments, the image processing condition may include atransparency processing switching timing of the first and second imagesor the transparency processing area of the entire display area of thedisplay device.

According to example embodiments, a control device for constructionmachinery may synthesize a first image and a second image captured froman upper camera installed in a driver cabin of the constructionmachinery and a lower camera installed in a front body into one image,transparency-process at least one of the first and second images to betransparent in the synthesized image according to a posture change of awork apparatus, and display the transparency-processed image through adisplay device 300.

The first image and/or the second image may be transparency-processed inthe synthesized image according to the posture of the work apparatussuch as a position of a bucket or a boom, to remove a blind spot that isobscured by the front work apparatus. Thus, an operator's cognitiveability may be increased to secure stability, to thereby prevent safetyaccidents.

Further, a transparency processing area may be set according to theoperator's selection, thereby improving the degree of freedom in usingthe transparency processed image, and an efficient system configurationmay be provided.

However, the effect of the inventive concept may not be limited thereto,and may be expanded without being deviated from the concept and thescope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings.

FIG. 1 is a side view illustrating a portion of construction machineryin accordance with example embodiments.

FIG. 2 is a side view illustrating bucket elevation positions accordingto rotation angles of a boom in FIG. 1 .

FIG. 3 is a block diagram illustrating a control system for theconstruction machinery in FIG. 1 .

FIG. 4 is a flow chart illustrating a control method for a wheel loaderin accordance with example embodiments.

FIG. 5 is a view illustrating a screen displayed on a display device ina driver cabin when a bucket is lower than a predetermined position.

FIG. 6 is a view illustrating a screen displayed on a display device ina driver cabin when a bucket is higher than a predetermined position.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Hereinafter, preferable embodiments of the present invention will beexplained in detail with reference to the accompanying drawings.

In the drawings, the sizes and relative sizes of components or elementsmay be exaggerated for clarity.

It will be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of example embodiments.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting of exampleembodiments. As used herein, the singular forms “a,” “an” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. It will be further understood that the terms“comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which example embodiments belong. Itwill be further understood that terms, such as those defined in commonlyused dictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art andwill not be interpreted in an idealized or overly formal sense unlessexpressly so defined herein.

Example embodiments may, however, be embodied in many different formsand should not be construed as limited to example embodiments set forthherein. Rather, these example embodiments are provided so that thisdisclosure will be thorough and complete, and will fully convey thescope of example embodiments to those skilled in the art.

FIG. 1 is a side view illustrating a portion of construction machineryin accordance with example embodiments. FIG. 2 is a side viewillustrating bucket elevation positions according to rotation angles ofa boom in FIG. 1 . FIG. 3 is a block diagram illustrating a controlsystem for the construction machinery in FIG. 1 . Although a wheelloader 10 is illustrated in FIG. 1 , a control device of constructionmachinery according to example embodiments is not limited to being usedonly in the wheel loader, but may be applied to an industrial vehiclesuch as an excavator, a forklift, etc. Hereinafter, for convenience ofdescription, only the wheel loader 10 will be described.

Referring to FIGS. 1 to 3 , construction machinery 10 may include avehicle body 12, 13, a driver cabin 40, and a work apparatus. Thevehicle body of the wheel loader 10 in FIG. 1 may include, for example,a front body 12 and a rear body 14 rotatably connected to each other.The front body 12 may include the work apparatus and a front wheel 70.The rear body 14 may include the driver cabin 40, an engine bay (notillustrated) and a rear wheel (not illustrated).

The work apparatus may include a boom 20 and a bucket 30. The boom 20may be freely pivotally attached to the front body 12, and the bucket 30may be freely pivotally attached to an end portion of the boom 20. Theboom 20 may be coupled to the front body 12 by a pair of boom cylinders22, and the boom 20 may be pivoted upwardly and downwardly by expansionand contraction of the boom cylinders 22. A tilt arm 34 may be freelyrotatably supported on the boom 20, almost at its central portion. Oneend portion of the tilt arm 34 may be coupled to the front body 12 by apair of bucket cylinders 32 and another end portion of the tilt arm 34may be coupled to the bucket 30 by a tilt rod, so that the bucket 30 maypivot (crowd and dump) as the bucket cylinder 32 expands and contracts.

Additionally, the front body 12 and the rear body 14 may be rotatablyconnected to each other through a center pin 16 so that the front body12 may swing side to side with respect to the rear body 14 by expansionand contraction of a steering cylinder (not illustrated).

A travel apparatus for propelling the wheel loader 10 may be mounted atthe rear body 14. An engine (not illustrated) may be provided in theengine bay to supply an output power to the travel apparatus. The travelapparatus may include a torque converter, a transmission, a propellershaft, axles, etc. The output power of the engine may be transmitted tothe front wheel 70 and the rear wheel through the torque converter, thetransmission, the propeller shaft and the axles, and thus the wheelloader 10 may travels.

A hydraulic pump (not illustrated) for supplying a pressurized hydraulicoil to the boom cylinder 22 and the bucket cylinder 32 of the workapparatus may be mounted at the rear body 14. The hydraulic pump may bedriven using at least a portion of the power outputted from the engine.For example, the output power of the engine may drive the hydraulic pumpfor the work apparatus and a hydraulic pump for the steering cylindervia a power transmission device such as a gear train.

The hydraulic pump may supply the hydraulic oil to drive the workingdevice, and may be divided into a variable capacity type and a constantcapacity type. A pump control device (EPOS, Electronic Power OptimizingSystem) may be connected to the variable capacity hydraulic pump, and anamount of the hydraulic oil discharged from the variable capacityhydraulic pump may be controlled by the pump control device. A maincontrol valve (MCV) including a boom control valve and a bucket controlvalve may be installed on a hydraulic circuit connected to the hydraulicpump. The hydraulic oil discharged from the hydraulic pump may besupplied to the boom cylinder 22 and the bucket cylinder 32 through theboom control valve and the bucket control valve of the main controlvalve MCV. The main control valve (MCV) may supply the hydraulic oildischarged from the hydraulic pump to the boom cylinder 22 and thebucket cylinder 32 according to a pilot pressure signal in proportion toan operation rate of an operating lever. Thus, the boom 20 and thebucket 30 may be driven by the pressure of the hydraulic oil dischargedfrom the hydraulic pump.

The driver cabin 40 may be installed on the vehicle body of theconstruction machinery, and in case of the wheel loader, the drive cabin40 may be installed on the rear body 14. A maneuvering device may beprovided within the driver cabin 40. The maneuvering device may includean acceleration pedal, a brake pedal, an FNR travel lever, the operatinglevers for operating the cylinders such as the boom cylinder 22 and thebucket cylinder 32, etc.

As mentioned above, the wheel loader 10 may include a travelingoperating system for driving the travel apparatus via the powertransmission device and a hydraulic operating system for driving thework apparatus such as the boom 20 and the bucket 30 using the outputpower of the engine 100.

Hereinafter, a control system for the construction machinery will beexplained using the wheel loader as an example.

As illustrated in FIG. 3 , a control system for construction machinerymay include a camera portion 100 installed in the wheel loader 10 tophotograph the front of the wheel loader 10, a work apparatus posturedetection portion configured to detect a posture of the work apparatusconnected to the front body 12, an image processing portion 200configured to process an image from the camera portion 100, and adisplay device 300 configured to display the image processed by theimage processing portion 200. Additionally, the control system forconstruction machinery may further include an input portion configuredto set an image processing condition in the image processing portion200.

The image processing portion 200 for the wheel loader 10 such as aportion of an engine control unit ECU or a vehicle control unit VCU, ora separate control unit may be mounted in the rear body 14. The imageprocessing portion 200 may be implemented with dedicated hardware,software, and circuitry configured to perform the functions describedherein. These elements may be physically implemented by electroniccircuits such as logic circuits, discrete components, microprocessors,hard-wired circuits, memory elements, wiring connections, and the like.

In example embodiments, the camera portion 100 may monitor the front ofthe wheel loader 10 when the wheel loader 10 travels or works, and mayinclude a plurality of cameras. In particular, the camera portion 100may include an upper camera 110 installed in the driver cabin 40 andconfigured to photograph the front of the driver cabin 40 to capture afirst image and a lower camera 120 installed in the front body 12 andconfigured to photograph the front of the front body 12 to capture asecond image. Although one upper camera and one lower camera areillustrated in FIGS. 1 and 2 , it may not be limited thereto, and aplurality of the upper cameras and a plurality of the lower cameras maybe provided.

The upper camera 110 may have a first vertical viewing angle (Field ofView, FoV) θv1 and a first horizontal viewing angle based on the frontdirection of the wheel loader. For example, the first vertical viewingangle may have an angular range of 60 degrees to 120 degrees. The lowercamera 120 may have a second vertical viewing angle θv2 and a secondhorizontal viewing angle based on the front direction of the wheelloader. For example, the second vertical viewing angle may have anangular range of 60 degrees to 120 degrees.

The first image may be an image captured with a focus on a front upperregion through the upper camera 110, and the second image may be animage captured with a focus on a front lower region through the secondcamera 120.

By setting the first vertical viewing angle θv1 of the upper camera 110and the second vertical viewing angle θv2 of the lower camera 120 topartially overlap, the first image and the second image may partiallyoverlap each other.

In example embodiments, the work apparatus posture detection portion maydetect whether the work device invades a transparency processing area ina display area to be described later. As described later, transparencyprocessing may be performed on the captured image when the workapparatus invades a predetermined position, that is, an actual positioncorresponding to the predetermined transparency processing area amongthe entire display area of the display device 300, so that an operator'sview may be secured. The posture of the work apparatus may include aposition of the bucket 30 (a height of the bucket from the ground) or aposture of the boom 20 (a rotation angle of the boom). To this end, thework apparatus posture detection portion may include a boom angle sensor24 for detecting the position of the bucket 30 or the posture of theboom 20. In addition, the work apparatus posture detection portion mayinclude a bucket angle sensor (not illustrated) for detecting a relativerotation angle between the boom 20 and the bucket 30. The work apparatusposture detection portion may include a displacement sensor fordetecting a stroke of the cylinder driving the boom 20, in place of theboom angle sensor 24. Further, the work apparatus posture detectionportion may include an image analysis device that analyzes an image ofthe work apparatus captured through the camera to determine the postureof the work device.

The boom angle sensor 24 may detect the rotation angle of the boom 20and provide information on the position of the bucket 30 based on therotation angle of the boom 20. As illustrated in FIG. 2 , the rotationangle of the boom 20 may be an angle θ between an extension line L atthe lowest position (0%) of the boom 20 (bucket 30) and an extensionline R at an elevated position of the boom 20. The rotation angle of theboom 20 at the highest position of the boom 20 (max boom height) isθmax·height, and in this case, the boom (bucket) position may be themaximum height (100%).

In example embodiments, the image processing portion 200 may beinstalled in a form of a control device built in the control device orthe display device of construction machinery. The image processingportion 200 may include an image synthesizer 210 configured tosynthesize the first image and the second mage into one image and atransparency processor 220 configured to transparency-process at leastone of the first and second images to be transparent according to theboom position detected by the boom position detection portion. The imageprocessing portion 200 may further include an image rendering portion230 configured to render the image processed synthetic image into a 3Dimage. The functions of the image synthesizer 210, the transparencyprocessor 220 and the image rendering portion 230 may be implementedthrough a single processor such as GP or CPU for image processing, orthrough computational processing of separate processors.

The image synthesizer 210 may match the first image and the second imagecaptured by the upper camera 110 and the lower camera 120 to findportions of images that overlap (are duplicated) in the first and secondimages and synthesize the overlapping portions of the images into onesynthesized image. The transparency processor 220 may performtransparency processing on at least one of the first and second imagesin the synthesized image according to the detected posture of the workapparatus. The image rendering portion 230 may process the synthesizedimage to be displayed like a real image and output the renderingprocessed synthesize image to the display device 300.

The transparency processor 220 may process the first and second imagesto be transparent only in a partial area of the entire display area ofthe display device 300. The transparency processing area may be definedto include an area in which the front view is obscured by the front workapparatus including the elevating boom 20 and the bucket 30.

In the transparency processing, the portions of the first image and/orthe second image within the transparency processing area of thesynthesized image may be removed or translucent processed to overlap thebackground image, or an outline of an exterior of the first image and/orthe second image may be two-dimensionally drawn with a line or dottedline so that only the shape may be identified. For example, the portionsof the first image or the second image in the transparency processingarea may be removed from the synthesized image using an alpha blendingtechnique.

In example embodiments, the transparency processor 220 may performtransparency processing in response to a case in which at least a partof the work apparatus invades a position corresponding to thetransparency processing area. When the bucket or boom position is lowerthan a predetermined position (transparency switching position), whichcan be determined that the at least a part of the work apparatus doesnot invade the transparency processing area, the second image in thesynthesized image may be transparency-processed to be transparent. Onthe other hand, when the bucket or boom position is the predeterminedposition (transparency switching position), which can be determined thatthe at least a part of the work apparatus invades the transparencyprocessing area, the first image in the synthesized image may betransparency-processed to be transparent. The predetermined position ofthe boom may be set such that the rotation angle θ of the boom 20 iswithin a range of 15 degrees to 20 degrees.

When the bucket 30 is positioned between the lowest position (0%) andthe predetermined bucket position, that is, the transparency switchingposition which is the boundary of the transparency processing area, thesecond image captured from the lower camera 120 may betransparency-processed, so that an object implemented by the uppercamera 110 may be displayed as a main point (focus). In the second imagecaptured from the lower camera 120, when the bucket 30 is in arelatively low position, the front view of the front body 12 may beobscured by the front work apparatus including the boom 20 and thebucket 30. The transparency processor 220 may process the second imageto be transparent and display the first image as a focus to therebyprevent the front view from being obscured by the front work apparatus.

When the bucket 30 is positioned between the predetermined bucketposition and the highest position (100%) of the transparency processingarea, the first image captured from the upper camera 110 may betransparency-processed, so that an object implemented by the lowercamera 120 may be displayed as a main point (focus). In the first imagecaptured from the upper camera 110, when the bucket 30 is in arelatively high position, the front view of the front body 12 may beobscured by the front work apparatus including the boom 20 and thebucket 30. The transparency processor 220 may process the first image tobe transparent and display the second image as a focus to therebyprevent the front view from being obscured by the front work apparatus.

When the bucket 30 is lifted or lowered to pass through thepredetermined bucket position (transparency switching position), animage located in the transparency processing area transparency-processedby the transparency processor 220 may be converted from the second imageto the first image or from the first image to the second image.

Alternatively, the transparency processor 220 may transparency-processthe second image in the synthesized image to be transparent when therotation angle θ of the boom is within a first angle range,transparency-process the first and second images in the transparencyprocessing area of the synthesized image to be transparent when therotation angle θ of the boom is within a second angle range, andtransparency-process the first image in the synthesized image to betransparent when the rotation angle θ of the boom is within a thirdangle range. For example, the first angle range may be within 0 degreeto 15 degrees, the second angle range may be within 15 degrees to 25degrees, and the third angle range may be within 25 degrees to 45degrees.

In example embodiments, an image processing condition in the imageprocessing portion 200 may be set through an input portion 400. Forexample, the image processing condition may include a location, a size,etc. of the transparency processing area. As the transparency processingarea is determined, the transparency switching position of the first andsecond images, the transparency processing area in the entire displayarea of the display device 300, and the like may be set. For example,the transparency switching position may represent a boundary position ofthe transparency processing area, and when the bucket 30 moves to belocated at the boundary of the transparency processing area, the bucket30 may be considered to be located at a predetermined position fortransparency switching. The size and location of the transparencyprocessing area, the transparency switching timing, etc. may be fixedlyset by a manufacturer according to a type of equipment, and may befreely changed and set by the operator or maintenance personnel.

For example, the input unit 400 may be implemented in a form of aninstrument panel option, and the operator may change the timing pointfor the transparency switching, the area to be processed fortransparency, and the like through the input unit 400.

As mentioned above, when the transparency processing area and thetransparency switching point are set, the display device 300 may displayan image by dividing the image captured by the camera portion into thetransparency processing area A and an external area of the transparencyprocessing area A. The display device 300 may additionally display anoutline of the transparency processing area A such that the transparencyprocessing area A can be distinguished, or may not display the outlineof the transparency processing area and may display thetransparency-processed image to be connected to an image of the externalarea of the transparency processing area A.

Additionally, the display device 300 may display the first image in theexternal area of the transparency processing area A, and may display atransparency image in which at least one of the first image and thesecond image is displayed as a focus according to the progress of thetransparency processing within the transparency processing area A. Forexample, the display device 30 may display the transparency image inwhich both the first and second images are translucent.

For example, when the bucket 30 is located in the external area of thetransparency processing area A, the display device 300 may display onlythe first image that interconnects the transparency processing area Aand the external area of the transparency processing area A.Alternatively, a transparency image in which the first image isdisplayed as a focus may be displayed within the transparent processingarea A. In this case, the operator may recognize that the display device300 displays the first image as a whole due to the transparency image inwhich the first image is displayed as the focus. Additionally, when atleast a portion of the bucket 30 is located within the transparencyprocessing area A, the display device 300 may display atransparency-processed image in which the second image is displayed as afocus or the second image within the transparency processing area A, andmay display the first image in which only the image in the transparencyprocessing area A is excluded, in the external area of the transparencyprocessing area.

Hereinafter, a method of controlling construction machinery using thecontrol system for construction machinery in FIG. 3 will be explained.The following description will also be described based on the wheelloader as in the above-described method.

FIG. 4 is a flow chart illustrating a control method for a wheel loaderin accordance with example embodiments. FIG. 5 is a view illustrating ascreen displayed on a display device in a driver cabin when a bucket islower than a predetermined position. FIG. 6 is a view illustrating ascreen displayed on a display device in a driver cabin when a bucket ishigher than a predetermined position.

Referring to FIGS. 1 to 6 , first, a first image and a second imagecaptured respectively through an upper camera 110 and a lower camera 120installed in a wheel loader 10 may be synthesized (S100).

In example embodiments, the first image for the front of a driver cabin40 may be obtained using the first camera 110 installed in the drivercabin 40. The second image for the front of a front body 12 may beobtained using the second camera 120 installed in the front body 12.

The first image may be an image captured with a focus on a front upperregion portion through the upper camera 110, and the second image may bean image captured with a focus on a front lower region through thesecond camera 120. A first vertical viewing angle θv1 of the uppercamera 110 and a second vertical viewing angle θv2 of the lower camera120 may be set to partially overlap, the first image and the secondimage may partially overlap each other.

In example embodiments, an image synthesizer 210 of an image processingportion 200 may match the first image and the second image capturedthrough the upper camera 110 and the lower camera 120 to synthesize thefirst image and the second mage into one image.

Then, a rotation angle of a boom 20 connected to the front body 12 maybe detected (S120).

In example embodiments, information on a position of a bucket 30, thatis, a height of the bucket 30 from the ground may be detected by a boomangle sensor 24. An elevated height of the bucket may be determined fromthe rotation angle of the boom 20 detected by the boom angle sensor 24.

As illustrated in FIG. 2 , the rotation angle of the boom 20 may be anangle θ between an extension line L at the lowest position (0%) of theboom 20 and an extension line R at an elevated position of the boom 20.The rotation angle of the boom 20 at the highest position of the boom 20(max boom height) is θmax·height, and in this case, the bucket positionmay be the maximum height (100%).

Then, whether or not the bucket position is lower than a predeterminedposition (transparency switching position) may be determined (S110). Thepredetermined position may be the transparency switching position whichis the boundary of the transparency processing area. That is, thecomparison between the position of the bucket and the predeterminedposition may include checking whether a part of the bucket 30 or theboom 20 is located within the transparency processing area A. When thebucket or the boom is lower than the predetermined position, the secondimage in the synthesized image may be transparency processed (S130), andwhen the bucket or the boom is higher than the predetermined position,the first image in the synthesized image may be transparency processed(S132). Here, the predetermined position may be a lower boundary of thepredetermined transparency processing area A based on an image displayedthrough a display device 300. Then, the transparency-processedsynthesized image may be displayed through the display device 300(S140). In this case, the display device 300 may display the first imagein an external area of the transparency processing area A.

In example embodiments, a transparency processor 220 of the imageprocessing portion 200 may perform transparency processing at least oneof the first and second images to be transparent in the synthesizedimage according to the detected boom position.

The transparency processor 220 may transparency-process the first andsecond images to be transparent only in a partial area of the entiredisplay area of the display device 300. The transparency processing areamay be defined to include an area in which the front view is obscured bythe front work apparatus including the elevating boom 20 and the bucket30.

In the transparency processing, the portions of the first image and/orthe second image within the transparency processing area of thesynthesized image may be removed or translucent processed to overlap thebackground image, or an outline of an exterior of the first image and/orthe second image may be two-dimensionally drawn with a line or dottedline so that only the shape may be identified. For example, the portionsof the first image or the second image in the transparency processingarea may be removed from the synthesized image using an alpha blendingtechnique.

As illustrated in FIG. 5 , when the bucket 30 or the boom 20 ispositioned between the lowest position (0%) and the predetermined bucketor boom position, the second image captured from the lower camera 120may be transparency-processed, so that an object implemented by theupper camera 110 may be displayed as a main point (focus) within thetransparency processing area A of the display device 300. When thebucket 30 or the boom 20 is in a relatively low position, a portion ofthe front work apparatus obscuring the front view in the second imagemay be transparency-processed so that the object O may be identified inthe synthesized image.

As illustrated in FIG. 6 , when the bucket 30 or the boom 20 ispositioned between the predetermined position and the highest position(100%), the first image captured from the upper camera 110 may betransparency-processed, so that an object implemented by the lowercamera 120 may be displayed as a main point (focus) within thetransparency processing area A of the display device 300. When thebucket 30 or the boom 20 is in a relatively high position, a portion ofthe front work apparatus obscuring the front view in the first image maybe transparency-processed so that the object O may be identified in thesynthesized image.

For example, the predetermined position of the boom may be set such thatthe rotation angle θ of the boom 20 is within a range of 15 degrees to20 degrees.

Alternatively, the second image in the synthesized image may betransparency-processed to be transparent when the rotation angle θ ofthe boom is within a first angle range, the first and second images inthe transparency processing area of the synthesized image may betransparency-processed to be transparent when the rotation angle θ ofthe boom is within a second angle range, and the first image in thesynthesized image may be transparency-processed to be transparent whenthe rotation angle θ of the boom is within a third angle range. Forexample, the first angle range may be within 0 degree to 15 degrees, thesecond angle range may be within 15 degrees to 25 degrees, and the thirdangle range may be within 25 degrees to 45 degrees.

In example embodiments, an image processing condition for transparencyprocessing the first and second images may be set. The image processingcondition in the image processing portion 200 may be set through aninput portion 400. For example, the image processing condition mayinclude a location, a size, etc. of the transparency processing area. Atransparency switching timing of the first and second images may bedetermined based on the position of the bucket 30 or the bucket 20 andthe predetermined bucket or boom position. The transparency processingarea may be selected according to a type of equipment.

For example, the input unit 400 may be implemented in a form of aninstrument panel option, and the operator may change the timing pointfor the transparency switching, the area to be processed fortransparency, and the like through the input unit 400. The input unit400 may be provided in a form of a separate manipulation device providedin the driver cabin, a manipulation device integrally provided with thedisplay device, or a touch screen constituting a display screen of thedisplay device. Thus, the operator may set various image processingconditions such as setting a periphery of the object O (see FIGS. 5 and6 ) requiring attention during work as the transparent processing area.

As mentioned above, the first image and the second image captured fromthe upper camera 110 installed in the driver cabin 40 of the wheelloader 10 and the lower camera 120 installed in the front body 12 may besynthesized into one image, at least one of the first and second imagesmay be transparency-processed to be transparent in the synthesized imageaccording to the position of the bucket 30 or the boom 20 connected tothe front body 12, and the transparency-processed image may be displayedthrough the display device 300.

When the bucket 30 or the boom 20 is in a relatively low positionbetween the lowest position (0%) and the predetermined bucket position,in the second image captured from the lower camera 120, the front viewof the front body 12 may be obscured by the front work apparatusincluding the boom 20 and the bucket 30. When the bucket 30 is in arelatively high position between the predetermined bucket position andthe highest position (100%) of the transparency processing area, in thefirst image captured from the upper camera 110, the front view of thefront body 12 may be obscured by the front work apparatus including theboom 20 and the bucket 30.

The first image and/or the second image may be transparency-processed inthe synthesized image according to the position of the bucket 30 or theboom 20, to remove a blind spot that is obscured by the front workapparatus. Thus, the operator's cognitive ability may be increased tosecure stability, to thereby prevent safety accidents.

The foregoing is illustrative of example embodiments and is not to beconstrued as limiting thereof. Although a few example embodiments havebeen described, those skilled in the art will readily appreciate thatmany modifications are possible in example embodiments withoutmaterially departing from the novel teachings and advantages of thepresent invention. Accordingly, all such modifications are intended tobe included within the scope of example embodiments as defined in theclaims.

What is claimed is:
 1. A control system for construction machinery, the control system comprising: an upper camera installed in a driver cabin of the construction machinery to photograph the front of the driver cabin; a lower camera installed in a vehicle body of the construction machinery to photograph the front of the vehicle body; a work apparatus posture detection portion configured to detect a posture of the work apparatus connected rotatably to the vehicle body; an image processing portion configured to synthesize first and second images captured from the upper camera and the lower camera into one image, and configured to transparency-process at least one of the first and second images in the synthesized image according to the posture of the work apparatus detected by the work apparatus posture detection portion; and a display device configured to display the synthesized image transparency-processed by the image processing portion, wherein the image processing portion transparency-processes the first image in the synthesized image when at least a part of the work apparatus invades a predetermined position, and the image processing portion transparency-processes the second image in the synthesized image when the work apparatus does not invade the predetermined position.
 2. The control system of claim 1, wherein the entire display area of the display device includes a predetermined transparency processing area and an external area of the predetermined transparency processing area, and the image processing portion processes the first and second images to be transparent in the predetermined transparency processing area.
 3. The control system of claim 1, further comprising: an input portion configured to set an image processing condition in the image processing portion.
 4. The control system of claim 3, wherein the image processing condition includes a transparency processing switching timing of the first and second images or a predetermined transparency processing area of the entire display area of the display device.
 5. A method of controlling construction machinery, the method comprising: obtaining a first image of the front of a driver cabin of the construction machinery from an upper camera installed in the drive cabin; obtaining a second image of the front of a vehicle body of the construction machinery from a lower camera installed in the vehicle body; detecting a posture of a work apparatus connected to the vehicle body; synthesizing the first and second images into one image; transparency-processing at least one of the first and second images in the synthesized image according to the detected posture of the work apparatus; and displaying the transparency-processed image through a display device, wherein transparency-processing the at least one of the first and second images comprises: transparency-processing the first image in the synthesized image when at least a part of the work apparatus invades a predetermined position; and transparency-processing the second image in the synthesized image when the work apparatus does not invade the predetermined position.
 6. The method of claim 5, wherein the entire display area of the display device includes a predetermined transparency processing area and an external area of the predetermined transparency processing area, and the first and second images are processed to be transparent in the predetermined transparency processing area.
 7. The method of claim 5, further comprising: setting an image processing condition for transparency processing of the first and second images.
 8. The method of claim 7, wherein the image processing condition includes a transparency processing switching timing of the first and second images or a predetermined transparency processing area of the entire display area of the display device.
 9. Control system for construction machinery, the control system comprising: an upper camera installed in a driver cabin of the construction machinery to photograph the front of the driver cabin; a lower camera installed in a vehicle body of the construction machinery to photograph the front of the vehicle body; an image processing portion configured to synthesize first and second images captured from the upper camera and the lower camera into one image, and configured to transparency-process at least one of the first and second images in the synthesized image; and a display device configured to display the synthesized image transparency-processed by the image processing portion, wherein the entire display area of the display device includes a predetermined transparency processing area in which the transparency-processed image is displayed and an external area of the predetermined transparency processing area, and wherein the image processing portion processes the first and second images to be transparent in the transparency processing area when at least a part of the work apparatus is located within the transparency processing area.
 10. The control system of claim 9, further comprising: an input portion configured to set an image processing condition in the image processing portion.
 11. The control system of claim 10, wherein the image processing condition includes a transparency processing switching timing of the first and second images or a size and location of the predetermined transparency processing area of the entire display area of the display device. 